Rotary cam controlled engine

ABSTRACT

A low speed, high torque internal combustion engine having radially reciprocating pistons. Cam follower rollers mounted on the radially inner end of the piston rods are engaged with cams to convert radial reciprocation of the pistons into rotation of an engine shaft. Adjustable guides engage guide rollers on the piston rods to constrain movement of the piston rods along the radial paths.

[ 1 Mar. 14, 1972 States Patent Ullifi iii Smith [54] ROTARY CAM CONTROLLED ENGINE 1,648,780 11/1927 Neusell......................................74/55 [72] Inventor: Ralph J. Smith, East Killingly, Conn.

[73] Assignee: Promoeo lnterprises Llmited [22] Filed:

Primary ExaminerWilliam F. O'Dea Assistant Examiner-Wesley S. Ratliff, Jr. Attorney-Clarence A. O'Brien and Harvey B. Jacobson Apr. 20, 1970 [57] ABSTRACT A low speed, high torque internal combustion engine having 21 Appl. No.: 30,093

"' radially reciprocating pistons. Cam follower rollers mounted on the radially inner end of the piston rods are engaged with earns to convert radial reciprocation of the pistons into rotation of an engine shaft. Adjustable guides engage guide rollers on the piston rods to constrain movement of the piston rods along the radial paths.

[51] Int.

[58] Field otSearch....

References Cited UNITED STATES. PATENTS Marchetti 4 Claims, 7 Drawing Figures 3 Sheets-Sheet 5 WWW; J. Smith BY @Mm ROTARY CAM CONTROLLED ENGINE This invention relates to a radial piston type of engine and more particularly to an engine in which the reciprocatory movement of the piston is converted into rotation of a shaft through cam means.

Various radial piston engines having cam connections between the piston rods and the engine shaft, are known. The construction of these engines is such, however, that excessive wear of parts makes prolonged engine operation impracticable. Further, extreme precision in the manufacture of the engine parts is required making engine construction and operation costly.

It is therefore an important object of the present invention to provide a radial piston-type engine of the aforementioned type which is relatively simple in construction and capable of operating with relatively high efficiency by providing adjustment facilities.

In accordance with the present invention, an internal combustion engine is formed from two or more units, each of which includes a pair of cylinder-piston sections disposed in 90 relationship to each other relative to a rotational axis of the engine shaft to which the pistons are operatively connected by means of a cam follower arrangement. Each piston is accordingly provided with a piston rod having cam engaging rollers disposed in eccentric relationship to each other and rotatable about an axis intersecting the radial path along which the piston rod is guided for movement by adjustable guide tracks engaged with guide rollers on the piston rod disposed in laterally spaced relation to the radial path along which the piston rod is reciprocated by its piston. The cam grooves associated with each of the engine units are angularly spaced from each other by 90 while the cylinder units are angularly spaced from each other by 45 for obtaining overlapping combustion cycles. Each engine unit undergoes two power strokes per cycle by utilizing a pair of pistons angularly spaced 90 from each other.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, hereof, like numerals refer to like parts throughout, and in which:

FIG. 1 is transverse sectional view through a typical engine constructed in accordance with the present invention.

FIG. 2 is a longitudinal sectional view through the engine taken substantially through a plane indicated by section line 22 in FIG. 1.

FIG. 3 is a partial transverse sectional view, taken substantially through a plane indicated by section line 33 in FIG. 2.

FIG. 4 is an enlarged partial sectional view taken substantially through a plane indicated by section line 4-4 in FIG. 1.

FIG. 5 is an elevational view of one of the parts associated with the engine.

FIG. 6 is an enlarged partial sectional view taken substantially through a plane indicated by section line 6-6 of FIG. 11.

FIG. 7 is a perspective view showing disassembled portions of the engine.

Referring now to the drawings in detail, and initially to FIGS. l and 2, the engine generally denoted by reference numeral it) includes a generally cylindrical housing generally referred to by reference numeral 12 made up of axially assembled sections M and 16 each of which encloses a separate engine unit. Although two of such housing sections are shown, it will be appreciated that any number of sections and associated engine units may be assembled to form an engine in accordance with the desired power requirements. In the illustrated embodiment, the housing section M is closed at one axial end by an end wall 18 mounting a bearing assembly through which an engine drive shaft 22 is journaled. The en gine drive shaft extends through the housing assembly and is joumaled at the opposite axial end by another bearing as sembly in an end wall 26 adapted to be secured to the open axial end of the housing section 16. Superchargers or blowers and 24 are driven by the shaft supply air to the intakes and scavenge the adjacent engine units. The housing assembly is also provided with an intermediate wall section 28 spacing the two engine units respectively enclosed by the housing sections. The engine shaft 22 is journaled with the intermediate wall portion 28 of the housing section 16 by an intermediate bearing assembly 30 thereby establishing a rotational axis for the engine shaft which is common to both of the engine units.

Since each of the engine units are similar in construction and operation, only the engine unit enclosed within the housing section M will be described in detail. This engine unit includes a pair of cylinder formations 32 and 34 projecting radially from the housing section in angularly spaced relation to each other. A spark plug device 34 is mounted on the radially outer end of each cylinder formation which encloses a combustion chamber 36 on the radially outer side of a piston element 38 reciprocably mounted within the cylinder formation. A fuel mixture is introduced into the combustion chamber 36 for ignition by the spark plug device 34 and the combustion products are exhausted from the chamber during each engine cycle causing reciprocation of the piston element 38. Thus, valves and timing devices for controlling intake of the fuel mixture, ignition thereof and exhaust of combustion products will be associated with the engine and are operative in a manner well-known to those skilled in the art.

Each piston element 38 has a piston rod 40 connected thereto. The piston rod 40 is reciprocated along a radial path by the piston element within a radial cutout 42 formed within a circular plate M secured to the housing section by means of a plurality of fasteners 46 located adjacent its periphery as shown in FIGS. 1, 2 and 5. In the illustrated embodiment, there are two radial cutouts 42 located 90 from each other relative to ,the rotational axis of the engine shaft 22 which extends through the central opening 48 in the disk 44. The cutouts 42 thus are radially aligned with the two cylinder formations 32 disposed in 90 relationship to each other as aforementioned. The disk 44 is axially located between a pair of cam assemblies 50 that are splined to the engine shaft 22 on either side of the piston rods. The cam assemblies 50 are mirror images of each other and are operatively associated with the two piston rods 40, each of which is provided with a cam follower assembly 52 at its radially inner end.

Referringnow to FIGS. 1, 7 and i in particular, the cam follower assembly 52 includes an arcuate enlargement 54 on the piston rod 40 at its radial inner end fixedly mounting a shaft 56 parallel to the engine shaft 22 and having eccentric portions 5% at the opposite axial ends. Thus, the shaft 56 establishes a pair of radially spaced axes intersecting the radial path along which the piston rod 46 is reciprocated by its piston element. On each axial end portion of the shaft 56, a pair of eccentrically related cam rollers 60 and 62 are rotatably mounted. Each pair of cam rollers is received within aligned cam grooves M on the confronting sides of the cam assemblies 50. Each cam groove is accordingly provided with radially spaced groove sections 66 and 68 respectively receiving the cam rollers 60 and 62. Because of this arrangement, dead-centering of the pistons is avoided.

The follower assembly 52 at the radial inner end of each piston rod 40, is also provided with a pair of guide rollers 70 rotatably mounted by pins 72 that extend through the piston rod enlargement 541 in laterally spaced relation to the radial path along which it is reciprocated within the cutout 42 of the guide plate 44. The rollers 70 accordingly project laterally from the piston rod at opposite sides thereof and are V-shaped in cross section so as to engage a track surface 74 on a guide element 76. Guide elements 76 are thus mounted along the parallel edges of the radial cutouts 42 by means of adjustment slots 78 and fastener elements tit) as more clearly seen in FIGS. 1, 6 and 7. The guide elements 76 may therefore be accurately positioned upon the guide plate 44 in order to constrain movement of the piston rods to the radial paths so that the full power. of the piston elements 38 may be transmitted to the cam assemblies without any power loss which would other wise occur as a result of column buckling or deflection. The

reciprocatory movement of the piston rods is of course converted into rotation of the engine shaft 22 by means of the cam assemblies 50.

Each housing section 14 and 16 encloses an engine unit as hereinbefore described which operate in the same manner. However, the operational cycles of the engine units overlap each other and toward this end, the cam grooves 64 associated with the cam assemblies in the respective engine units, are angularly spaced from each other by 90. The cylinder formations on the other hand are angularly spaced by 45 as more clearly seen in FIG. 1.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

' 1. An internal combustion engine comprising a housing, a drive member mounted by the housing for rotation about a rotational axis, cam means rotationally fixed to the drive member within the housing, piston means movably mounted by the housing, cam follower means connected to the piston means for engagement with the cam means to impart rotation to the drive member in response to reciprocation of the piston means and guide means engageable with the cam follower means for constraining reciprocation of the piston means along a radial path extending from said rotational axis, said cam follower means includes a rigid piston rod extending from the piston means, a pair of eccentrically related rollers rotatably mounted on the piston rod about axes intersecting one of said radial paths, and a guide roller rotatably mounted on the piston rod in laterally spaced relation to said radial path in engagement with the guide means.

2. The combination of claim 1 wherein said cam means includes a cam member having a cam groove receiving the eccentrically related rollers.

3. The combination of claim 2 wherein said guide means includes a disc fixed to the housing, a guide element having a track surface engaged by the guide roller on the piston rod, and means adjustably positioning the guide element on the disc in parallel spaced relation to said radial path and the cam member.

4. The combination of claim 1 wherein said guide means includes an annular disc fixed to the housing, a guide element having a track surface engaged by the guide roller on the piston rod, and means adjustably positioning the guide element on the annular disc in parallel spaced relation to said radial path. 

1. An internal combustion engine comprising a housing, a drive member mounted by the housing for rotation about a rotational axis, cam means rotationally fixed to the drive member within the housing, piston means movably mounted by the housing, cam follower means connected to the piston means for engagement with the cam means to impart rotation to the drive member in response to reciprocation of the piston means and guide means engageable with the cam follower means for constraining reciprocation of the piston means along a radial path extending from said rotational axis, said cam follower means includes a rigid piston rod extending from the piston means, a pair of eccentrically related rollers rotatably mounted on the piston rod about axes intersecting one of said radial paths, and a guide roller rotatably mounted on the piston rod in laterally spaced relation to said radial path in engagement with the guide means.
 2. The combination of claim 1 wherein said cam means includes a cam member having a cam groove receiving the eccentrically related rollers.
 3. The combination of claim 2 wherein said guide means includes a disc fixed to the housing, a guide element having a track surface engaged by the guide roller on the piston rod, and means adjustably positioning the guide element on the disc in parallel spaced relation to said radial path and the cam member.
 4. The combination of claim 1 wherein said guide means includes an annular disc fixed to the housing, a Guide element having a track surface engaged by the guide roller on the piston rod, and means adjustably positioning the guide element on the annular disc in parallel spaced relation to said radial path. 